In addition to today's over-the-top (“OTT”) and traditional telecommunication service verticals provided by mobile operators, the 5G Radio Access Network (RAN) systems are expected to support emerging use cases with specific and sometimes critical QoS and QoE requirements such as Internet of Things (“IoT”) (including mission critical mobile-to-mobile (“M2M”)), vehicle-to-vehicle/infrastructure (V2X) communication, tactile Internet (such as remote factory/robotics control or augmented reality), smart buildings, sensor networks, etc.
In Long-Term Evolution (LTE), granularity of traffic and service differentiation is based on data bearer granularity with pre-configured QoS parameters (such as priority and guaranteed bit rate). Initially, mapping the traffic to data bearers is based on per-flow traffic flow templates (TFTs) (such as internet protocol (IP) addresses, ports and protocols) that may be established and modified through core-RAN and user equipment (UE) network signaling procedures. This makes traffic flow templates difficult to use to target short lived interactive IP flows as they might complete before the TFTs could have been established. Additionally, mapping packets based on TFTs requires a lookup from a TFT table at each packet. Thus, an in-band packet marking is created to carry the sub-service flow (SSF) identity to avoid the need for per-flow SSF identity signaling. As such, with a SSF already established, even the first packet of short lived IP flows may be mapped to the corresponding SSF and receive a corresponding QoS/QoE treatment.
Traditionally, LTE has a low architectural limit on the number of dedicated bearers that may be established for the same UE. This inherently limits the granularity of service differentiation. As such, a flexable number of SSFs and/or real-time adjusable mapping of SSFs to radio buffers and the dynamic programming of the radio buffers to reflect the QoS/QoE requirements of the traffic mix are desired.
Proprietary mechanisms may use in-band signaling, such as packet marking, to attach bearer level QoS information to the User-Plane (U-plane) packets. Existing mechanisms are still acting on the entire traffic mix carried by the bearer. For example, they do not differentiate and manage traffic below the bearer aggregation. As such, a data bearer could be roughly paired with a SF. Moreover, the existing mechanisms are targeting bearer QoS changes, that are executed according to pre-defined static rules, and they lack dynamic intra-bearer traffic separation.
When considering the relations between the SSFs and the bearers, clear differentiation should be made between the role of the data bearers and mechanisms used for mapping packets to bearers. The role of the data bearers may relate to addressing a traffic mix that is to receive a statically pre-configured relative QoS at the radio interface. The mechanism used for mapping packets to bearers may relate to a general packet radio service (GPRS) Tunneling Protocol (“GTP”) of a service that can be regarded as an in-band marking interface. The inability of the bearer based QoS architecture to fit for QoE enforcement is not caused by the use of GTP or any kind of packet marking, but the bearer's inflexible granularity of traffic multiplexing (such as practically the whole data traffic of the UE). The inability may also be caused by the static association of the bearer with a limited set of QoS parameters and the shortcomings of the underlying QoS architecture. Conversely, using an in-band mechanism or packet packing to map U-plane packets to a logical multiplexing group does not make the mechanism become a bearer.